Method and apparatus for lining a pipe

ABSTRACT

The method for rehabilitating a damaged section of a pipe without a need for a resin absorbent liner is provided. The method includes pumping a low viscosity material towards a damaged section of pipe and changing the viscosity prior to dispensing of the material. For example, the material may be partially cured prior to dispensing. The partially cured or higher viscosity material is compressed between an inflating bladder and interior wall of the pipe, and the material that is allowed to fully cure. The bladder either can then be removed from the pipe or could be allowed to maintain in the pipe providing a new interior surface for the repaired pipe.

FIELD OF THE INVENTION

The present invention relates generally to a method and apparatus forlining a pipe. More particularly, but not exclusively, the inventionrelates to a method and apparatus for pumping a curable material a longdistance, and changing the viscosity of the material prior to dispensingat a final location.

BACKGROUND OF THE INVENTION

A method used for repairing pipelines and other structures includes theuse of a liner tube having a felt layer on its inside and having aprotective layer made of polymer or other plastic material on itsoutside. The liner tube is vacuum-impregnated with a resin mix in whatis commonly referred to as a “wet-out” process. Just prior towetting-out the liner, a catalyst is mixed with the resin so as toactivate the resin and cause it to begin curing and hardening. The resinimpregnated liner tube is then inverted into the pipeline so that thefelt layer is inverted from the inside of the tube to the outside. Oncethe resin cures and hardens, the liner provides a new lining for thepipeline. Some resins are set to cure at ambient temperatures. In someinstances, steam or hot water is applied inside the lining tube to speedthe cure time

One problem with the method is that the catalyst must be mixed with theresin before the liner tube is wet-out and before positioning the linertube at the damaged section of pipe. Once the catalyst is applied to theresin, the resin begins curing and time is of the essence in order tohave the liner tube in place within the pipeline to be repaired. If theresin hardens before the liner tube is properly positioned within thepipe, it may require that a portion of the existing pipeline be dug upand replaced. If, on the other hand, a resin mix with a longer cure timeis used to ensure adequate working time to install the liner,productivity suffers as the crew waits for the liner to cure and harden.

Aside from the loss in productivity, there are also additional costsinvolved in retarding or accelerating the cure time. For example,following the wet-out process the lining tube can be packed in ice andstored in a refrigerated compartment of the truck to retard or preventthe resin from curing. To accelerate the cure time, a large boiler andother equipment is required at the job site. Such equipment and theassociated labor required all add to the total installation cost.

Use of a pre-formed liner tube itself can be problematic. For example,the liner tube is normally fabricated off-site in a factory and thus thedimensions of the host pipe and the section of pipe in need of repairmust be known in advance to construct a liner of appropriate size.Conventional liners are also susceptible to shrinkage and otherstructural problems.

Some attempts have been made to spray or sling grout onto the interiorsurface of the pipe. Such methods are also problematic. Spraying orslinging grout inside the pipe does not provide for a uniform wallthickness of the lining. The grout or other material applied will alsotend to run away from the crown of the pipe and toward the bottom of thepipe before the material can cure and harden. This sagging effectresults in the uneven distribution of lining material around theinterior of the pipe. The lining also does not have a smooth surface.Still further yet, the spraying or slinging method is not effective inareas of the pipe where there is ground water infiltration.

In addition, at times the grout or resin must be pumped a long distanceprior to being sprayed or slung on the wall. To be able to pump thematerial the required distance, the viscosity of the grout or resinmaterial must be low enough to not become clogged or otherwise preventthe movement of the material. However, a material of such a viscositywould sag or fall off of the interior wall of the pipe or structure, asnoted above. In addition, most resins or grouts require mixing of twoparts to cause the material to begin to cure. Thus, two separatedispensing tubes must be provided so that the two parts of the materialdo not mix and begin to cure, which would prevent pumping of thematerial.

Therefore, there is a need in the art for a method and apparatus forpumping a curable material a long distance, which overcomes the need fora pre-formed or resin-absorbent liner, and that also overcomes theproblem of the material sagging or not sticking to the wall of thestructure.

SUMMARY OF THE INVENTION

It is therefore a primary object, feature, and/or advantage of thepresent invention to overcome deficiencies in the art.

It is another object, feature, and/or advantage of the present inventionto provide a method and apparatus for lining a structure without the useof a resin-absorbent liner.

It is still another object, feature, and/or advantage of the presentinvention to provide a method and apparatus for pumping a curablematerial a long distance.

It is yet another object, feature, and/or advantage of the presentinvention to provide a method and apparatus that provides for changingthe viscosity of a curable material during the pumping of the materialand prior to dispensing.

It is a further object, feature, and/or advantage of the presentinvention to provide a method and apparatus for partially curing acurable material while pumping the material to a final destination.

It is yet a further object, feature, and/or advantage of the presentinvention to provide a method and apparatus for repairing a pipe using aone-part, UV cured resin pumped a long distance.

It is still a further object, feature, and/or advantage of the presentinvention to provide a method and apparatus that includes a viscositymodifying region in a pumping and dispensing apparatus to partially curea material during transport.

It is another object, feature, and/or advantage of the present inventionto prevent an inflatable bladder from becoming buoyant and controlling auniform wall thickness.

These and/or other objects, features, and advantages of the presentinvention will be apparent to those skilled in the art. The presentinvention is not to be limited to or by these objects, features andadvantages. No single embodiment need provide each and every object,feature, or advantage.

According to an aspect of the present invention, a method ofrehabilitating a damage section of a pipe that obviates the need for aresin absorbent liner is provided. The method includes positioning abladder in a pipe. A material capable of curing and hardening isdispensed between an exterior surface of the bladder and the pipe. Thematerial capable of curing and hardening is at least partially curedprior to being dispensed. The at least partially cured material iscompressed between the bladder and the pipe, and the material is allowedto continue to cure.

The material capable of curing and hardening can be a one part, UV-curedresin, can be a two-part, mix-cured resin, or can be a water-activatedhydrophilic or hydrophobic resin or grout. In any case, the resin beginswith a low viscosity such that it can be pumped a long distance. Beforedispensing, the resin or grout material is partially cured to raise theviscosity, which provides for better retention at the dispensing pointof the material. Therefore, the material can be partially cured by lightinitiators, by mixing the multiple parts, or by adding water prior todispensing. The bladder can be prepositioned in the structure andinflated, or can be inverted, with the material dispensed behind aninverting face of the bladder.

According to another aspect of the present invention, a method ofrehabilitating a damage section of a pipe that obviates the need for aresin absorbent liner is provided. The method includes positioning abladder in a pipe; pumping a material capable of curing and hardeningand having a first viscosity within the pipe; changing the viscosity ofthe material being pumped in the pipe; dispensing the materialcomprising the changed viscosity between an exterior surface of thebladder and the pipe; compressing the material between the bladder andthe pipe; and allowing the material to cure.

According to yet another aspect of the present invention, a method ofdispensing a material a distance in a delivery apparatus having astarting end and a dispensing end is provided. The method includes, inpart, pumping a material capable of changing viscosities through thedelivery apparatus. The viscosity of the material is at least partiallychanged while pumping the material and before the material reaches thedispensing end of the delivery apparatus. The material comprising the atleast partially changed viscosity is eventually dispensed out of thedispensing end of the delivery apparatus.

The method can be used for the repair of pipes or other structures, inpainting, in medical procedures, or generally any other use thatincludes drilling, borings, material handling, the transport of a liquidor resin-like material over a relatively long distance. The methodallows the material to be dispensed in a changed state after beingpumped the distance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a pipe being repaired according to anembodiment of the present invention.

FIG. 2 is a view similar to FIG. 1, showing the repair progressingthrough the pipe.

FIG. 3 is an elevation and partial sectional view of a tractor andextruder used in the pipe repair according to an embodiment of thepresent invention.

FIG. 4 is a sectional view of the tractor of FIG. 3.

FIG. 5 is a perspective view of the extruder of FIG. 3.

FIG. 6 is a sectional view of a sewer pipe with a damaged section ofpipe lined according to an alternative embodiment of the presentinvention.

FIGS. 7A-7C are enlarged sectional views, illustrating various forms ofa bladder for use in an alternative embodiment of the present invention.

FIG. 8 is a sectional view of a pipe being repaired according to anotherembodiment of the present invention.

FIG. 9 is a view similar to FIG. 8, showing the repair progressingthrough the pipe.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a main pipe 10 is shown extending between anupstream manhole 12 and a downstream manhole 14. Lateral pipes 18 extendfrom the main pipe. The main pipe 10 shown in FIGS. 1 and 2 includes adamaged section 16 in need of repair. While the present invention isshown for use with sewer pipe repair, the present invention can beutilized for repairing other types of pipe, this including but notlimiting to gas, water, oil, steam, and compressed air pipes.

To repair the damaged section 16 of the main pipe 10, a tractor 22, anextruder 24, and a bladder 30 are inserted within the pipe 10. Thetractor 22 includes a plurality of wheels 23 for movement of the tractor22 about the interior 20 of the main pipe 10. The extruder or dispensingapparatus 24 is attached to an end of the tractor 22. The bladder 30, asshown in FIGS. 1 and 2, may be positioned through or adjacent a portionof the extruder 24 and tractor 22 such that a sufficient length ofbladder 30 is positioned within the pipe 10 to allow the bladder 30 toexpand, such as by inflation, to allow the bladder 30 to be expandedabout the full periphery of the damaged section 16 of the main pipe 10.

The tractor 22 and extruder 24 are connected to one another, and also toa resin hose 28. The resin hose 28 is connected to a resin reel 42, andis used to transport a resinous material 26 that is pumped via pump 41from a resin source 40. The pump 41 and resin source 40 may be locatedon a truck 44 positioned outside of the pipe system. The pump 41 is usedto pump resin 26 from the source 40 through the resin line 28 into,through, and out of the extruder 24.

As discussed above, the bladder 30 is positioned in the pipe 10,including adjacent to or through the tractor 22 and extruder 24. Shownin FIG. 1, the bladder 30 may be positioned through the extruder 24 butnot the tractor 22, or may be positioned adjacent both or through both.Positioned generally at each end of the main pipe 10 are first andsecond gaskets 36, 38. The gaskets 36, 38 may comprise a NSF/ANSI 61material, which may be a hydrophilic material. The first and secondgaskets 36, 38 will aid in sealing the ends of the main pipe 10 suchthat any dispensed material will not go outside the area in need ofrepair. The bladder 30 includes an open end 33 attached to a bladderroller 50 including an inflation source 46, and an opposite closed end34 positioned at the opposite end of the pipe in need of repair. A rope48 may be extended through the bladder 30 and connected to the closedend 34 to aid in removal of the bladder 30 from the pipe in certainembodiments.

The resinous material 26 being pumped through the resin line 28, tractor22, and out the extruder or dispensing apparatus 24 may be a one part,ultraviolet (UV) cured resin. Other photo curing resins may also beused. The resin material 26 may have a low viscosity while being storedin the reservoir 40 and also while being pumped through the resin line28. However, the viscosity of the resin material 26 may be increased toa higher viscosity prior to being dispensed at the extruder 24.Therefore, the tractor 22 may include a light tunnel 34 therein. Thelight tunnel 54, as will be discussed below, will include lightinitiators 56 for at least partially activating and curing the UV-curedresin 26 as it is pumped through the tractor 22. The light tunnel 54 ofthe tractor 22 will increase the viscosity of the resin material 26prior to being dispensed via the extruder 24. As in known in the art, itis advantageous to have a higher viscosity material being pumped in amanner similar to that shown in FIG. 1 via the extruder 24 in between anexterior surface 32 of the bladder 30 and the interior 20 of the pipe 10such that the resin material 26 will not be able to drip or migrate fromthe periphery of the interior 20 of the pipe 10. The higher viscositywill allow the dispensed resin to maintain its position at the interior20 at the pipe 10, and prevent the inflated bladder from floating. Inaddition, fillers, such as carbon nanotubes or other like materials, maybe incorporated into the resin.

Therefore, as shown in FIGS. 1 and 2, the resin material 26 having a lowviscosity will be pumped through the resin line 28 from the reservoir 40towards the tractor 22. The light tunnel 54 of the tractor 22 will beginto at least partially cure the material 26, thus increasing viscosity ofthe material as it is moved through the tractor 22. The materialcontinues through the extruder 24, beginning in the extruder entrance 58and exiting at the extruder exit 60, and is dispensed between anexterior surface 32 of the bladder 30 and the interior 20 of the pipe10. As the bladder 30 is being inflated through the pipe 10 as thetractor 22 and extruder 24 are moved through the pipe, the bladder 30will press the dispensed material against a wall of the pipe 10, whereit is allowed to further cure and harden.

Other components shown in FIGS. 1 and 2 that may be included withembodiments of the present invention include one or more cameras 52positioned on or at the tractor 22. The cameras 52, which are connectedto an area external of the pipes via a camera line 53, will aid inviewing the interior of the pipe 10, including the dispensement of theresin material 26 between the bladder 30 and the pipe 10. This will aidin moving the tractor 22 through the pipe 10. The tractor 22 may bemoved in the pipe 10 by pulling or rolling the resin line 28 via thevariable speed controlled resin hose reel 42. Thus, the speed of theresin hose reel 42 may be adjusted as needed according to what is shownby the cameras 52 and the pipe 10. However, it should be appreciatedthat not all embodiments require a camera or cameras within the pipe,and the speed of travel by the tractor 22 in the pipe 10 may be presetsuch that it is automatic through the pipe based on prior knowledge ofthe dispensing rate of the resin material 26 by the extruder 24. Inaddition, other sensors besides cameras may be used.

As discussed, the bladder 30 may be connected to a bladder roller 50 atan open end 33 of the bladder 30. The bladder roller 50 may include aninflation source 46, such as an air source, for inflating the bladder asthe repair assembly (tractor, extruder, etc.) moves through the pipe 10.The inflation source 46 will provide air or another fluid to theinterior of the bladder 30 such that the inflating edge of the bladderwill remain close to the dispensing head or extruder exit 60 such thatthe bladder 30 will press the resin material 26 between the exterior 32of the bladder 30 and the interior 20 of the pipe 10 as it is beingdispensed. The present invention contemplates that the resin material 26may be dispensed either in front of or behind the inflating edge of thebladder 30. It is also contemplated that, instead of the tractor 22moving due to the resin hose reel 42, the inflation of the bladder 30may also press against the extruder exit 60 end of the extruder 24 suchthat the continued inflation of the bladder 30 will move the tractor 22and extruder 24 through the pipe 10. The extruder 24 may also include aplate (not shown) or other device for resting adjacent the inflatingportion of the bladder 30. In addition, a rope 48 may be connected tothe reel 50 and closed end 34 of the bladder 30 such that the rope maybe pulled or reeled once the resinous material has cured to remove thebladder 30 from the interior of the pipe 10. The resin hose itself couldalso be pulled to move the components through the pipe. This wouldnegate the need for the use of the tractor. However, it is alsocontemplated in other embodiments that the bladder may remain within thepipe 10 when permanently bonded to the curable material.

While FIGS. 1 and 2 show the bladder 30 and resin material 26 blockingthe lateral pipes 18 extending from the main pipe 10, it should beappreciated that the present invention contemplates that the lateralpipes 18 may be reinstated once the resin material 26 has cured, thusreinstating access to the main pipe 10 via the lateral pipes 18. Thelateral pipes 18 may be reinstated as is known the art, such as bycutting the resin material and/or bladder material at the opening of thelateral pipes 18.

FIG. 3 is a side elevation and partial sectional view of a tractor 22and extruder 24 that may be used for the pipe repair according toembodiments of the present invention. As discussed, a resin line 28 isconfigured to pump the resin material 26 from the reservoir 40 to theextruder 24. As shown in FIG. 3, the resin line 28 may pass through thetractor 22 and into the extruder entrance 58 of the extruder 24. Asshown by the sectional view of the tractor 22, the interior of thetractor 22 includes a light tunnel 54 comprising a plurality of lightinitiators 56. As discussed above, the resin material 26 may be onepart, UV-cured resin having an initial low viscosity. A low viscositymay be in the range of approximately 500 centipoise (cP), while a highviscosity may be approximately 50,000-100,000 cP. The low viscosity ofthe resin will allow the resin to be pumped easily over long distances.However, it may be desired to dispense a resin having a higher viscositywithin the pipe 10. The light tunnel 54 comprising the plurality oflight initiators 56 comprise UV light sources such that the resinmaterial 26 passing through the transparent resin line 28 through thetractor 22 will be initiated by the light initiators 56 to begin curing.This curing will raise the viscosity of the resin as it moves throughthe tractor 22 and into the extruder 24. Thus, the resin being dispensedby the extruder 24 will have a higher viscosity that will maintain itsposition at the interior 20 of the pipe 10. Thus, there will be lesschance of the resin material 26 running from the crown of pipe or thepipe and/or sagging. Furthermore, the higher viscosity material willmitigate floating of the bladder. With low viscosity, the bladder canmove relative to the material. However, as the material has a higherviscosity, the thickness of the material will reduce the likelihood ofthe bladder floating.

FIG. 4 shows a sectional view of the tractor 22 according to anembodiment of the invention. As discussed, the tractor 22 includes alight tunnel 54 comprising a plurality of light initiators 56. The lightinitiators 56 may comprise a ring of UV producing lights. Furthermore,as shown in FIG. 4, the light tunnel 54 may comprise a plurality of therings of UV lights. In addition, LED lights or any other type of lightsmay be used. The resin passing through the resin line 28 within thetractor 22 will thus be activated by the UV lights of the lightinitiator 56 to begin curing, thus raising the viscosity of thematerial. In addition, as the tractor 22 may include cameras 52positioned at the front end of the tractor 22, the cameras 52 may beable to view the viscosity of the resinous material 26 being dispensedfrom the extruder 24. If the viscosity of the resinous material is toohigh, the light or some of the lights of the light tunnel 54 may bedecreased in intensity or turned off to stop the curing of the materialthrough the tractor 22 all dependent on the flow rate of the material.In the alternative, if the viscosity of the resinous material 26 beingdispensed is too low, the intensity of some or all of the lights of thelight tunnel 54 may be increased or turned on to increase the activationand curing of the resinous material through the light tunnel 54 of thetractor 22. Thus, the control of the viscosity of the resinous material26 being dispensed by the extruder 24 can be adjusted on the fly from anexternal location of the pipe 10. Furthermore, the curing can be haltedcompletely by turning off the UV lights.

It should be noted that the process can be computer controlled, with theintensity of the light being controlled by the flow rate of the materialbeing pumped. For example, to move through the pipe at 10 feet/minuteand having a pipe length of 500 feet, the install time would be 50minutes. For an 8-inch pipe versus an 18-inch pipe, much more materialwill need to be pumped for the 18-inch pipe, and therefore, the lightintensity will need to be increased.

While a one part, UV-cured resin, along with light initiators 56 hasbeen disclosed for changing the viscosity of the resinous material 26from a generally low viscosity to a higher viscosity during pumping anddispensing of the material, it should be appreciated that other mannersof changing the viscosity may be included as part of the presentinvention. For example, if a thermoset resin is utilized with thepresent invention, the tractor 22 may include a heat source and a heattunnel therein. The resinous material 26 may be pumped from thereservoir 40 at a low viscosity over a long distance and towards thetractor 22. While passing through the tractor 22, the material may bepassed via a heat source, such as heat lamps, electrical coils, or thelike, to begin activation and at least partial curing of the material26. This activation will raise the viscosity of the material as it movesthrough the tractor and towards the extruder or dispensing apparatus 24.Other one part activating resin materials may be activated accordinglyas they are passed through or adjacent the tractor 22 in a similarmanner.

FIG. 5 is a perspective view of an example of an extruder head ordispensing apparatus 24 for use with the present invention. The extruder24 includes an entrance end 58 and an opposite exit 60. The entrance 58is generally connected to the tractor 22 and in communication with theresin line 28 for receiving the partially cured resinous material 26having a higher viscosity. One or more extruding tubes 62 connect theentrance 58 and exit 60 of the extruder 24. As shown in FIG. 5, threeextruder tubes 62 are radially positioned between the entrance 58 andexit 60. The radial positioning of the tube 62 will divert amounts ofresinous material 26 such that the resinous material 26 will bedispensed at a generally equal amount radially around the extruderaperture 64 at the extruder exit 60. Thus, the positioning of the tubeswill aid in providing that the resinous material 26 extruded generallyaround the full interior 20 of the pipe 10 as the tractor 22 andextruder 24 are moved through the pipe 10. While the extruder exit 60and extruder aperture 64 are shown to be generally circular, it shouldbe contemplated that any shape may be used, such as according to theshape of the pipe or location being repaired. In addition, the numberand orientation of extruder tube(s) 62 may also be varied as needed.

Also shown in FIG. 5 is an extruder bladder aperture 66 and a bridge 68positioned between two of the tubes 62. As mentioned above, the bladder30 may be positioned in the pipe 10 prior to being inflated therein. Toensure that the bladder 30 is out of the way during dispensing of theresinous material by the extruder 24, the bladder 30 may be run throughthe aperture 66 in the extruder exit 60 and may be positioned on eitherside of the bridge 68. The positioning of the bladder 30 in this mannerwill allow the bladder to remain out of the dispensing direction of theextruder 24, as well as out of the way of the moving tractor 22/extruder24 through the pipe 10. Furthermore, it is contemplated that the bladdermay also be strung through the tractor 22, or it may be positionedgenerally adjacent the tractor between the tractor 22 and the pipe 10.

Still further, it is contemplated that the bladder 30 may be invertedthrough the pipe 10 instead of being prepositioned within the pipe 10.In such embodiments, the bladder 30 will have an inverting face that ispositioned generally adjacent the exit 60 of the extruder 24 such thatthe inverting bladder face will continue expanding at the extruder exit60 as the extruder 24 and tractor 22 are moved through the pipe 10.

The invention provides numerous advantages over prior methods of piperepair. For example, the use of a single component, UV-cured resinrequires only one hose 28 and one pump 41 and no static mixing chamber.As the UV-cured resin cures rather quickly, the viscosity of the resinmay be changed just prior to dispensing of the resin such that a lowviscosity resin may be pumped over the long distance between thereservoir 40 and the dispensing area within the pipe 10, e.g. 500-800feet. Furthermore, the curing of the one part resin can be controlled asthe lights of the light tunnel may be turned on and off quickly to beginor halt curing of the resin. Furthermore, the intensity of the lightwithin the light tunnel may be adjusted to affect the curing rate of theresin as it passes through the tunnel.

The resin line 28 may be opaque between the reservoir 40 and the tractor22, and may be translucent or transparent within the tractor to allowthe UV emitting light initiators 56 to begin curing the resin therein.

It should be appreciated that the ability to transport a low viscosityresin over long distance is beneficial in the art as less energy will berequired via the pump to move the resin from the reservoir 40 to thedispensing area. However, it should also be appreciated that thechanging of the viscosity of the resin from the low viscosity to a highviscosity just prior to dispensing of the resin will still allow theresin to not sag or move at the point of dispensement between thebladder 30 and the pipe 10.

As discussed above, once the resin material 26 is dispensed in the pipe10, the bladder 30 is continued to inflate to press the resin betweenthe bladder 30 and the pipe 10. The inflation is maintained until theresin has fully cured, thus repairing the wall or a portion of the wallof the pipe 10. After the resin has cured, the bladder 30 may be removedfrom the pipe 10 by pulling the rope 48 connected to the closed end 34of the bladder 30. In other embodiments, however, it may be desired toleave the bladder 30 in the pipe 10 after the resinous material 26 hascured.

FIG. 6 shows an embodiment of the bladder 30 remaining in the pipe 10after the resinous material 26 has cured. The curing of the resinousmaterial 26 may create a chemical bond between the material 26 and theexterior of the bladder 30 such that the bladder 30 will remain attachedto the resinous material 26. The smooth interior surface of the bladder30 will provide a smooth surface for the repaired pipe 10.

FIGS. 7A-7C show another embodiment where the bladder 30 is remainedwithin the pipe 10. FIGS. 7A-7C show a mechanical connection between theresinous material 26 and the bladder 30. The Figures show the exteriorsurface 32 of the bladder 30 having an uneven surface 70 and includinghook-like projections 72 extending therefrom. The hook-like projections72 will form a mechanical bond or connection between the bladder 30 andthe resinous material 26, such that the bladder 30 will remain connectedor affixed to the resinous material 26. FIGS. 7A-7C show variousconfigurations of the hook-like projections 72 of the uneven exteriorsurface 70 of the bladder 30. However, it should be appreciated thatother forms of projections 72 may be provided at the uneven exterior 70of the bladder 30 to create a mechanical bond between the bladder 30 andthe resinous material 26.

FIGS. 8 and 9 provide additional embodiments of the method of piperepair according to the present invention. FIGS. 8 and 9 provide anothermethod for pumping low viscosity resins over a long distance andchanging the viscosity prior to dispensing the resin to repair a pipe10. However, in FIGS. 8 and 9, a two-part resin is shown. Theembodiments shown in FIGS. 8 and 9 include a first reservoir 82 having afirst part of a resinous material, and a second reservoir 86 having asecond part of a resin material 92. The two parts are pumped via firstand second pumps 84, 88 through first and second hoses 78, 80, andtowards a tractor 74 positioned within a pipe 10. In the embodimentsshown in FIGS. 8 and 9, the tractor 74 includes a mixing chamber 90therein to allow the first and second parts of the resinous material 92to mix. When practicing this method one would need to know the gel timefor the mixed resin and relate that the speed the tractor moves throughthe pipe. It should also be noted that a two part material that has along pot time and requires heat to cure could be mixed together andpumped through a single hose and activated at the tractor as describedto change viscosity.

As the first and second parts of the resinous material 92 combine, theywill begin to cure. The initial curing of the materials will increasethe viscosity of the components of the resin in the mixing chamber 90such that a higher viscosity will be dispensed by the extruder 24.Therefore, an extruder 24 as was shown and described previously may alsobe used for these embodiments. However, similar to the previousembodiments, the bladder 30 may be prepositioned within the pipe 10 andthrough the extruder 24, or may be inverted through the pipe as thetractor 74 and extruder are moved in the pipe. Furthermore, the bladder30 may be removed from the pipe after the resinous material 92 hascured, or it may be left in the pipe to provide a smooth interiorsurface after the resinous material 92 has cured. In addition, thetractor 74 also includes wheels 76 for aiding in the movement, cameras52 for providing a view within the pipe 10 as the pipe is beingrepaired, and camera line 53 for connecting the cameras to an areaexternal of the pipe 10.

It should be appreciated that the embodiments shown in FIGS. 8 and 9provide another method of repairing the pipe that allows for a lowviscosity resin to initially be pumped from the reservoir and towards atractor and dispenser. The low viscosity of the resin being moved fromthe reservoir towards the tractor and dispenser will allowed the resinto be moved over long distances without requiring a great amount ofenergy or pumping force, while also allowing for the use of a smallerdiameter hose. However, the embodiments also provide for increasing theviscosity of the resinous material prior to dispensing the material suchthat the higher viscosity material being dispensed will not sag or runabout the walls of the pipe 10. Instead of using a one-part curedmaterial, the embodiments shown in FIGS. 8 and 9 include multiple partresins. It should also be appreciated that the tractor may include othercontrols for controlling the rate of mixture between the first andsecond parts of the resinous material 92 to control the change inviscosity of the material from a low viscosity to a high viscosity.

The present invention relates to a technology that allows a lowviscosity material to be moved a long distance in a pipe or other memberbeing repaired or needing the material, while allowing for the viscosityof the material to be raised prior to dispensing of the material. Thus,while the invention has been shown and described relating to piperepair, it should appreciated that other fields may benefit from theinvention. For example, the health industry may benefit from pumping alow viscosity material through a tube or conduit, such as into a body orvia blood vessels. The viscosity could be changed at a specifiedlocation by the inclusion of light initiators, such as UV lights, toincrease the viscosity of the material being pumped prior todispensement. Other uses are also envisioned. For example, the presentinvention contemplates moving any types of liquid-like material arelatively long distance; wherein the viscosity of the material may bechanged prior to the final location of the material. The inclusion of aUV-cured resin that can be activated via light initiators at a desiredlocation may benefit many fields as can be appreciated by those in theart. The present invention allows for the material to be movedrelatively long distance with a lower concern that the material willclog in the pipe and will not reach the distance, while still insuringthat the material will have a higher viscosity at the point ofdispensement.

The invention has been shown and described above with reference toembodiments, and is understood that modifications, substitutions, andadditions may be made which are within the intended spirit and scope ofthe invention. For example, while the invention has been described asmoving through the pipe by the resin hose pulling the tractor or thebladder having an inverting face for pushing the dispenser and tractor,it should be appreciated that other means and manners of moving thetractor and dispenser through the pipe are envisioned, which may includea combination of pulling and pushing the tractor via the bladder and/orhose. Furthermore, other types of dispensing heads, such as spinningheads or slinging heads may be used as for dispensing of the materialwithin the pipe or other apparatus. The invention is only to be limitedby claims appended hereto.

What is claimed is:
 1. A method of rehabilitating a damaged section of apipe that obviates the need for a resin absorbent liner, comprising:positioning a bladder in a pipe; dispensing a material capable of curingand hardening between an exterior surface of the bladder and theinterior surface of the pipe; wherein the material capable of curing andhardening is at least partially cured prior to being dispensed;compressing the at least partially cured material between the bladderand the pipe; and allowing the material to continue to cure.
 2. Themethod of claim 1 further comprising removing the bladder from the pipeafter the material has cured.
 3. The method of claim 1 wherein thematerial capable of curing and hardening is a one-part, UV cured resin.4. The method of claim 3 further comprising pumping the UV-cured resinthrough a light tunnel to at least partially cure the resin prior todispensing.
 5. The method of claim 4 wherein the step of at leastpartially curing the resin increases the viscosity of the pumped resin.6. The method of claim 1 further comprising inflating the bladder in thepipe to compress the material between the bladder and the pipe.
 7. Themethod of claim 6 wherein the step of positioning the bladder in thepipe comprises inverting the bladder through the pipe.
 8. The method ofclaim 7 wherein the material is dispensed rearward of the inverting faceof the bladder between an exterior surface of the bladder and thedamaged section of pipe.
 9. The method of claim 8 wherein the materialis pumped from ahead of the inverting face of the bladder and toward theinverting face of the bladder.
 10. A method of rehabilitating a damagedsection of a pipe that obviates the need for a resin absorbent liner,comprising: positioning a bladder in a pipe; pumping a material capableof curing and hardening, and having a first viscosity within the pipe;changing the viscosity of the material being pumped in the pipe;dispensing the material comprising the changed viscosity between anexterior surface of the bladder and the pipe; compressing the materialbetween the bladder and the pipe; and allowing the material to cure. 11.The method of claim 10 wherein the change in viscosity comprises raisingthe viscosity of the material.
 12. The method of claim 11 wherein thematerial is a one-part, UV-cured resin.
 13. The method of claim 12wherein the step of changing the viscosity of the material comprisespumping the resin at least partially through a UV light source.
 14. Themethod of claim 10 wherein the material is a two-part resin.
 15. Themethod of claim 14 wherein the step of changing the viscosity of thematerial comprises mixing the two parts of the resin just prior todispensing the resin.
 16. The method of claim 10 further comprisingremoving the bladder from the pipe.
 17. The method of claim 10 whereinthe bladder remains in the pipe after the material has cured andhardened.
 18. A method of dispensing a material a distance in a deliveryapparatus having a starting end and a dispensing end, comprising:pumping a material capable of changing viscosities through the deliveryapparatus; at least partially increasing the viscosity of the materialwhile pumping the material and near the dispensing end of the deliveryapparatus; wherein the increase in viscosity is controlled; anddispensing the material comprising the at least partially changedviscosity out of the dispensing end of the delivery apparatus.
 19. Themethod of claim 18 wherein the material is a UV-cured material, and thestep of at least partially changing the viscosity comprises pumping thematerial adjacent a light source.
 20. The method of claim 19 wherein thelight source comprises a light tunnel including a plurality of lightinitiators.
 21. A method of rehabilitating a section of a pipeline,comprising: pumping a material capable of curing through a deliveryhose; and applying the material to the interior of the pipeline; whereinthe material has a viscosity of 10,000 cP or greater at a delivery endof the delivery hose.
 22. A method of rehabilitating a damaged sectionof a pipe that obviates the need for a resin absorbent liner,comprising: dispensing a one-part material capable of curing andhardening to the interior surface of the pipe; wherein the materialcapable of curing and hardening is at least partially cured prior tobeing dispensed; and allowing the material to continue to cure.